The present invention relates to improvements to the Foti probe described in my U.S. patent application Ser. No. 926,718, filed July 21, 1978, entitled "Closed Flow System Method and Apparatus For Inducing Nystagmus," which is a continuation of application Ser. No. 771,340, filed Feb. 23, 1977, now abandoned.
In my aforesaid patent application I describe a membrane-like probe having a flow-through path for nystagmus-inducing liquid, the probe expanding when filled with such liquid to conform to the contours of the ear canal. In one embodiment the insertion depth of the probe is standardized by an ear mold having a widened stop member which limits insertion by abutting the tragus. In order to prevent air from being trapped in the ear canal by the expanding probe, a vent tube extends through the length of the probe to a bore defined through the ear mold.
I have found that the vent tube unnecessarily complicates the construction of the probe and it is an object of the present invention to eliminate the vent tube while still preventing air from being trapped in the ear canal by the expanding membrane.